Investor focus on the ”big two” centred on what impact the devastation in Japan could have on their iron ore and coal exports.

Three uranium stocks accounted for more than $1 billion of the total losses, with Energy Resources Australia, Paladin Energy and Extract Resources all taking substantial hits.

Paladin chairman Rick Crabb said the market had been guilty of a ”substantial over-reaction” after his company’s share price fell 78¢ to $3.95, a fall of more than 16 per cent.

Paladin supplies uranium to American and Asian nuclear plants, and while it has several exploration projects in Australia and Canada, he said the Japanese incident was ”hardly likely” to affect the business.

”It’s not going to have much significance in the long term,” he said.

”Countries like China, Russia and India will still continue with their growth plans, it’s only likely to affect some decision-making authorities in certain countries like Australia or Germany.”

The Japanese crisis has sparked anti-nuclear rallies in Germany, and a promise from German Chancellor Angela Merkel to inspect the country’s reactors and hold a special nuclear summit with other European leaders.

Mr Crabb said it was ”ghoulish” and ”inappropriate” for anti-nuclear campaigners to be using the Japanese incident for political purposes while the search for survivors was still under way.

Energy Resources Australia – which is controlled by Rio Tinto – fell more than 12 per cent to $8.25, while Extract Resources – which is the indirect subject of a Chinese takeover bid – fell more than 7 per cent to $9.81.

The falls were even more spectacular for the junior miners, with several companies losing a quarter of their value in a single day of trading.

Peninsula Energy fell more than 29 per cent to close at 8.5¢, while Toro Energy fell more than 23 per cent to close at 10¢.

Patersons Securities analyst Simon Tonkin said the market had dealt harsher punishment to companies that were merely exploring for uranium, rather than those with mines already in production.

Uranium explorer Deep Yellow fell more than 21 per cent to close at 21.5¢.

Despite the gravity of the situation at Fukushima, the nuclear reactor has not been fully breached, and some believe the crisis could boost confidence in the nuclear industry, should the worst effects of a meltdown be avoided.

Toro Energy managing director Greg Hall said prevention of a big disaster at the site would be a significant ”success story” for the industry.

Hartleys analyst Dave Wall echoed that opinion.

”Our view is that if an earthquake, which measured 9 on the Richter scale, followed by a tsunami, does not result in a breach, this should ultimately be seen as confirmation of the safety of nuclear-powered energy,” said Mr Wall.

But he acknowledged that baser instincts, such as fear, may have a larger bearing on the market, particularly if the negative sentiment flows over to the ”regulatory environment”.

Australian policymakers and opinion leaders have appeared to be warming to nuclear power, with Resources Minister Martin Ferguson, Queensland Premier Anna Bligh and former prime minister Bob Hawke all calling for a policy rethink on uranium mining and nuclear power in Australia.

Nuclear power is virtually free of carbon emissions, prompting many advocates to suggest it is the ideal replacement for coal as a source of baseload power.

Australia has almost a quarter of the world’s uranium reserves, but the industry is constrained by a policy of only exporting to nations that are signatories to the nuclear non-proliferation treaty.